/* Copyright  2009
   @Author
   Richard Changde Yin            e-mail yinchangde@hotmail.com

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
   
/**
 * @filename: function/shift.cc
 */ 
#include <server_includes.h>
#include CSTDINT_H
#include <function/bit.h>

// Shift-functions, same as << and >> in C/C++

int64_t Item_func_shift_left::val_int()
{
  assert(fixed == 1);
  uint32_t shift;
  uint64_t res= ((uint64_t) args[0]->val_int() <<
                  (shift=(uint32_t) args[1]->val_int()));
  if (args[0]->null_value || args[1]->null_value)
  {
    null_value=1;
    return 0;
  }
  null_value=0;
  return (shift < sizeof(int64_t)*8 ? (int64_t) res : 0L);
}

int64_t Item_func_shift_right::val_int()
{
  assert(fixed == 1);
  uint32_t shift;
  uint64_t res= (uint64_t) args[0]->val_int() >>
                (shift=(uint32_t) args[1]->val_int());
    
  if (args[0]->null_value || args[1]->null_value)
  {
    null_value=1;
    return 0;
  }
  null_value=0;
  return (shift < sizeof(int64_t)*8 ? (int64_t) res : 0);
}

